Calibration error with hexadecimal characters in U1604A

TroubleshootingSummaryA calibration error code appears in a U1604A oscilloscope after doing self-calibrationQuestionAfter performing a self-calibration in a U1604A oscilloscope, the next calibration error code appears: Fail 0x03AFAnswerIf hexadecimal characters appear on the date/time display, this indicates that the memory backup battery is depleted and needs to be replaced.  It can also happen that handheld scope’s date/time display disappears for this same reason. This condition indicates that the internal memory battery level is low. When the battery level is low, the date/time display will first show hexa character and subsequently disappears. User is recommended to replace the internal memory battery based on the U1604A-02 Service Note (see attachment) or download from the next link: https://www.keysight.com/upload/cmc_upload/All/U1604A-02-Service_Note.pdfAttachmentshttps://keysightsales.my.salesforce.com/sfc/p/1a000000awb5/a/2L0000009JVN/FRF6cYjeybkbMX4LYld8uPns5rXf0YhG8EzgqNFrtMg